APPLICATION OF ULTRAHIGH VACUUM,

This popularized article gives a general description of several ultrahigh vacuum devices on unusually clean surfaces. Cursory descriptions are given with diagrams of a condensation pump, which condenses either a liquid or solid, an ion pump with a limited evacuating power, a diffusion pump limited in attaining a very low pressure, an evacuation pump used to obtain ultrahigh vacuum, a rotating pump used to obtain high vacuum. Thermonuclear reactions are introduced to affect the potential low-pressure and high-purity gas. Ultrahigh vacuum has opened new avenues for the electron tube industry.